Arnuz: Eh eh I've tried to make my luck in the same way, result: nothing to def and my wimpy hero has ridonculous resistance, yay he won't be charmed. Levels proposed: archery (not even a ranged hero, but found a bow) and spellcasting. No disablers that I know of with humans and air magic, the best I can get is the small draconian spitters, better than nothing...
I'm playing with the vault with the wizard, he's too slow to be with the hero anyway.
Other tricks to try to "donate" XP to your hero:
-Have other units wear down an enemy target, then have your hero try to hit it for the finishing blow.
-Have a unit, especially one with block (like Human Infantry), move around the tactical map just enough that it will only swing on the target once. This will burn some of the target's movement while maximizing your attacker's defense for the retaliation. You can adjust the number of attacks as needed (just be careful about eating attacks of opportunity).
-Human Swashbucklers (T2 unit, needs a War Hall) aren't great in auto-combat, but Fire Pistol and Taunt make them very useful in tactical combat. They can shoot high defense targets or (even better) taunt enemies and run away to distract opposing units. The taunted enemies generally try to avoid suffering attacks of opportunity, so you can spread your other units out some to make the victim run a long distance (sometimes the victim will run the gauntlet though; I'm not sure exactly when the AI considers this the better move). Also, be aware that taunted ranged units are actually pretty good about lining up shots on the harasser that just happen to place your other guys in the line of fire...
If you taunt a melee unit, you can mostly surround it with your units to get free retaliations when the victim runs after the taunting unit. If you have multiple units that can taunt, you can get something running back and forth, unable to be effective. In general the latest taunt is the one that takes priority, so you can taunt a victim that is getting too close to its first harasser to make the victim turn around. Non-taunting Swashbucklers can follow this up with guns to help whittle down a strong victim. Be aware that if you convert a taunted unit, it stays taunted for the full duration and will still try to attack the taunter even though both units are now on the same side!
Also, be aware while kiting that battles in Shadow Magic are capped at 25 rounds.